<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>练习</title>

  <style>
    #l1{
      color: green;
    }
    .b{
      color: blue;
    }
    h1,h2{
      background: yellow;
    }
    input[type = "submit"]{
      background: red;
    }
    input[type="button"]{
      color: pink;
    }
    *{
      border: 1px solid red;
    }
  </style>


</head>
<body>
<ul>
  <li id="l1">张学友</li>
  <li class="b">刘德华</li>
  <li>郭富城</li>
</ul>
<h1 class="b">悟空</h1>
<h1>八戒</h1>
<h1>唐僧</h1>
<h2>刘备</h2>
<input type="submit">
<input type="button" value="按钮"></input>

</body>
</html>